ZHCSD62F December 2012 – May 2021 LM25017
PRODUCTION DATA
- 1 特性
- 2 應用
- 3 說明
- 4 Revision History
- 5 Pin Configuration and Functions
- 6 Specifications
-
7 Detailed Description
- 7.1 Overview
- 7.2 Functional Block Diagram
- 7.3
Feature Description
- 7.3.1 Control Overview
- 7.3.2 VCC Regulator
- 7.3.3 Regulation Comparator
- 7.3.4 Overvoltage Comparator
- 7.3.5 On-Time Generator
- 7.3.6 Current Limit
- 7.3.7 N-Channel Buck Switch and Driver
- 7.3.8 Synchronous Rectifier
- 7.3.9 Undervoltage Detector
- 7.3.10 Thermal Protection
- 7.3.11 Ripple Configuration
- 7.3.12 Soft-Start
- 7.4 Device Functional Modes
-
8 Application and Implementation
- 8.1 Application Information
- 8.2
Typical Applications
- 8.2.1 Application Circuit: 12.5-V to 48-V Input and 10-V, 650-mA Output Buck Converter
- 8.2.2
Typical Isolated DC-DC Converter Using LM25017
- 8.2.2.1 Design Requirements
- 8.2.2.2
Detailed Design Procedure
- 8.2.2.2.1 Transformer Turns Ratio
- 8.2.2.2.2 Total IOUT
- 8.2.2.2.3 RFB1, RFB2
- 8.2.2.2.4 Frequency Selection
- 8.2.2.2.5 Transformer Selection
- 8.2.2.2.6 Primary Output Capacitor
- 8.2.2.2.7 Secondary Output Capacitor
- 8.2.2.2.8 Type III Feedback Ripple Circuit
- 8.2.2.2.9 Secondary Diode
- 8.2.2.2.10 VCC and Bootstrap Capacitor
- 8.2.2.2.11 Input Capacitor
- 8.2.2.2.12 UVLO Resistors
- 8.2.2.2.13 VCC Diode
- 8.2.2.3 Application Curves
- 9 Power Supply Recommendations
- 10Layout
- 11Device and Documentation Support
- 12Mechanical, Packaging, and Orderable Information
封裝選項
機械數據 (封裝 | 引腳)
散熱焊盤機械數據 (封裝 | 引腳)
- DDA|8
訂購信息
3 說明
LM25017 器件是一款 48V、650mA 同步降壓穩壓器，其集成了高側和低側金屬氧化物半導體場效應晶體管 (MOSFET)。LM25017 器件所采用的恒定導通時間 (COT) 控制方案無需環路補償，可提供出色的瞬態響應，并且可實現超高降壓比。導通時間與輸入電壓成反比，這使得整個輸入電壓范圍內的頻率幾乎保持恒定。高壓啟動穩壓器為 IC 的內部運行以及集成柵極驅動器提供了偏置電源。
峰值電流限制電路可防止出現過載情況。欠壓鎖定 (UVLO) 電路支持對輸入欠壓閾值和遲滯進行單獨編程。其他的保護特性包括：熱關斷和偏置電源欠壓閉鎖 (VCC UVLO)。
LM25017 器件采用 WSON-8 和 HSOP-8 塑料封裝。
器件信息
| 器件型號 | 封裝 | 封裝尺寸（標稱值） |
|---|---|---|
| LM25017 | HSOP (8) | 4.89mm x 3.90mm |
| WSON (8) | 4.00mm x 4.00mm |
典型應用原理圖